Antenna



FIG. 1 is an isometric view of an antenna, showing the design according to an embodiment;

FIG. 2 is a top plan view thereof, according to the embodiment;

FIG. 3 is an isometric view of an antenna, showing the design according to an additional embodiment; and,

FIG. 4 is a top plan view thereof, according to the additional embodiment. 

CLAIM The ornamental design for an antenna, as shown and described. 